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991.
工业园区已成为经济发展新的增长点,但是园区生态系统的忽略、发展与保护的不平衡等则阻碍着园区长远健康的发展。以泰州市为例,介绍了泰州市工业园区发展和建设的概况,从环境管理的现状入手,在分析现有环境管理突出问题及其成因的基础上,探讨和提出相应的建议。  相似文献   
992.
随着工业的发展和城市化进程的加快,城市恶臭污染影响日趋严重。目前,城市主要恶臭污染源包括城镇污水厂、生活垃圾填埋场以及化工、炼油等工业排放源,生活污染源对居住环境的影响也不容忽视。为切实改善城市居民生活环境质量,政府及管理部门应加快建立完善的恶臭环境标准体系,从管理层面、技术改进及公众监督三个方面共同促进我国环境空气质量与城市居住环境质量的改善。  相似文献   
993.
An approach combining nutrient budgets, dynamic modelling, and field observations of phytoplankton and nitrogen (N2)-fixing Lyngbya majuscula following changes in wastewater N loads, was used to demonstrate that Moreton Bay is potentially phosphorus (P) limited. Modelling and nutrient budgeting shows that benthic N-fixation loads are high, allowing the system to overcome any potential N-limitation. Phytoplankton biomass has shown little change from 1991 to 2006 in the sections of Moreton Bay most impacted by wastewater effluents, despite a large reduction in wastewater N loads from 2000 to 2002. This is consistent with modelling that also showed no reduction in primary productivity associated with reduced N loads. Most importantly, there have been rapid increases in the occurrence of N-fixing L. majuscula in Moreton Bay as wastewater P loads have increased relative to wastewater N loads. This is also consistent with modelling. This work supports the premise that there may be fundamental differences in nutrient limitation of primary production between subtropical and temperate coastal systems due to differences in the importance of internal nitrogen sources and sinks (N-fixation and denitrification). These differences need to be recognised for optimum management of coastal systems.  相似文献   
994.
Changes in the size of animal populations over time are mainly determined by demographic and environmental factors. Livestock population dynamics are additionally influenced by harvesting decisions taken by herders. In Bolivia, not much is known about current llama husbandry and the main influencing factors determining population sizes. We collected data on demography, environmental factors and market values affecting the current and future llama population in three different regions in Bolivia. We generated a population model and assessed the future development of the llama population including environmental factors (rangeland carrying capacity, disturbance phenomena), herd structure and dynamics, and economic market demands. We calibrated and validated the llama model on the basis of 20-year data sets of the regions of Oruro, Potosi and La Paz, respectively. Model calibration by means of the Gauss-Marquardt-Levenberg algorithm yielded a model efficiency of 0.94. For model validation, however, the simulation slightly overestimated the observed llama population yielding model efficiencies of 0.91 and 0.87 for Potosi and La Paz, respectively. Model outcomes were most sensitive to death and birth rates of juveniles and death rate of females compared to environmental or other demographic factors. Population trajectories approached an overall carrying capacity for Oruro, Potosi and La Paz of 8.8 × 105, 9.1 × 105, and 9.0 × 105 llama individuals after 100 years of simulation. Hence, detailed monitoring of demographic, environmental, and economic factors can improve predictions of llama population development over time. Further management should focus on improving birth rates and lowering female mortality through providing supplemental food and shelters against the harsh environmental conditions of the Andean highlands.  相似文献   
995.
佛波酯是麻疯树种子中的主要毒性物质之一.麻疯树种子经乙醇浸提、液液萃取和柱层析,获得佛波酯富集物.以TPA为外标,通过高效液相色谱(HPLC)定量分析佛波酯的含量,同时检测其对菜青虫的毒杀和拒食活性.结果显示,富集物中佛波酯含量达到0.817 35 mg mg-1.佛波酯富集物对3龄菜青虫具有显著的毒杀和拒食活性:毒杀活性表现为胃毒作用,胃毒活性具有明显的剂量效应和时间效应,48、72、120 h的佛波酯半致死浓度(LC50)分别为73.86、16.99、5.26μg mL-1;24、48 h的非选择拒食中浓度(AFC50)分别为9.81、5.39μg mL-1.图3表3参24  相似文献   
996.
对CDM市场的项目类型进行了归纳与分析,总结了CDM项目类型与项目注册过程中的问题,对CDM项目交易市场的现状及制度进行了探讨,并提出了相关建议。  相似文献   
997.
For industries in which where market prices of certain inputs are not available, measuring the degree of market power by using the markup over the marginal market cost may be inappropriate. With regard to the Korean iron and steel manufacturing industry, which is subject to environmental regulations, the calculation of the price of abatement capital is hindered by a lack of relevant data. To increase the reliability of market power markups, this paper estimates the restricted cost function in which abatement capital is assumed to be quasi-fixed at an optimal level and the supply relation. The degree of market power for the industry, measured as the ratio of the estimated market power markup to the supply price, was estimated to be 0.54 on average between 1982 and 2001. The results indicate that ignoring environmental regulations can overstate the degree of market power by approximately 12%.  相似文献   
998.
Aggregates represent one of the largest material flows in the UK economy; however, the importance of these minerals in underpinning economic activity is frequently not recognised. Features such as the spatial imbalance between resources and demand centres, exacerbated by changes in demographics and public perception, are placing increased pressure on the planning system to maintain supply. This paper sets out the direct and indirect economic contributions made by the indigenous aggregates industry to the English economy through Gross Value Added and employment sustained. It describes the key role of aggregates in construction activities, assesses the links between infrastructure development and economic growth. In 2005, aggregates extraction directly contributed £810 million of Gross Value Added to the English economy. Primary aggregates are, however, extracted at a cost to the environment and this cost, based on amenity value reduction, is estimated by updating previously published contingent valuation data. Estimates for the costs associated with carbon dioxide emissions are derived from values published by the European Union and, separately, by the UK Government. These two elements combined result in an environmental cost of indigenous extraction of £445 million in 2005. Additionally, an examination of the potential for a significant increase in the level of aggregate imports into England is made and the consequences assessed. This includes an evaluation of shipping costs and port capacity, and concludes that there are significant barriers to any substantial increase in the level of aggregate imports into England. As a consequence, indigenous supply is likely to predominate into the foreseeable future.  相似文献   
999.
Titania nanotubes are gaining prominence in photocatalysis, owing to their excellent physical and chemical properties such as high surface area, excellent photocatalytic activity, and widespread availability. They are easily produced by a simple and effective hydrothermal method under mild temperature and pressure conditions. This paper reviews and analyzes the mechanism of titania nanotube formation by hydrothermal treatment. It further examines the parameters that affect the formation of titania nanotubes, such as starting material, sonication pretreatment, hydrothermal temperature, washing process, and calcination process. Finally, the effects of the presence of dopants on the formation of titania nanotubes are analyzed.  相似文献   
1000.
采用静态暗箱-气相色谱法对2009年11月至2010年6月冬小麦(Triticum aestivum L.)生长季N2O排放通量进行田间原位观测,研究不同耕作方式(免耕、少耕、传统耕作)对太湖地区稻麦轮作系统麦季土壤N2O排放的影响。结果表明:有植株参与下免耕、少耕和传统耕作的冬小麦生长季N2O平均排放通量分别为63.75μg·m-2·h-1、39.94μg·m-2.h-1和48.83μg·m-2·h-1,无植株参与下分别为73.48μg·m-2·h-1、52.97μg·m-2·h-1和63.60μg·m-2·h-1,麦季N2O排放通量的季节变化与5 cm、10 cm土壤温度呈显著或极显著线性正相关(r=0.400*~0.654**,n=28)。小麦种植对N2O的排放影响较大,无植株参与的N2O季节总排放量显著高于有植株参与的处理(P〈0.05);耕作方式显著影响冬小麦农田N2O季节总排放量(P〈0.05),有植株参与下麦季N2O总排放量少耕较免耕和传统耕作分别减少37.3%和17.9%,无植株参与下分别减少28.0%和16.7%。研究表明太湖地区冬小麦采用少耕措施可减少麦季N2O的排放。  相似文献   
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